<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 300px;
            max-width: 200px;
            height: 100px;
            max-height: 200px;
            border:1px solid red;
            /* letter-spacing: 10px;*/        /*字符间距 */
            /* word-spacing: 20px; */          /*单词间距*/
            /* word-break: break-all; */      /*超出父元素自动换行（宽）*/
            /*overflow:hidden;*/                  /*超出父元素自动隐藏（高）*/
            overflow:scroll;
        }
    </style>
</head>
<body>
    <div>hello world<br>xxxxxx<br>xxxxxx<br>xxxxxx<br>xxxx<br>xxxxx<br>xxxx<br>xxxx<br>xxxxx<br>xxx<br>xx<br>xxxx<br>xxx<br>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx</div>
</body>
</html>